1. Field of the Invention
The present invention relates to a sheet feeding device that feeds sheets and to an image forming apparatus, such as a copying machine, a facsimile machine, and a printer, to which the sheet feeding device is applied.
2. Description of the Related Art
A sheet feeding device has been used to feed sheets to an image forming apparatus. Generally, the sheet feeding device is provided to the image forming apparatus, and feeds sheets piled inside the sheet feeding device to the image forming apparatus by separating the sheets one by one from the uppermost sheet in the pile using the pick-up roller or the like. Examples of the sheet feeding device include but not limited to a large capacity sheet feeding device external to the image forming apparatus and a sheet feeding cassette provided inside the image forming apparatus main body.
For the sheet feeding device, it is general to provide a guide inside the sheet feeding device. The guide restricts sheets piled inside the sheet feeding device to a specific position or prevents piled sheets from fluctuating or collapsing inside the device for a sheet to be picked up without fail. There is a sheet feeding device configured so as to accommodate therein sheets of a fixed size and there is another sheet feeding device configured so as to accommodate therein sheets of various sizes, such as A4-, A3-, B4-, and B5-size sheets, by making the position of the guide changeable.
To be more concrete, the sheet feeding device opens at the top surface and sheets to be piled are inserted and loaded in the sheet feeding device from the top surface direction. Sheets are normally piled in a horizontal posture inside the sheet feeding device. The guide is therefore provided in a direction perpendicular to the bottom surface of the sheet feeding device and one surface of the guide abuts on the piled sheets at one end. The position of sheets is thus restricted as one surface of the guide abuts on the sheets.
As an example of the sheet feeding device as above, there is a sheet feeding device disclosed in JP-A-2002-046869 (Reference D1). Reference D1 describes an external sheet feeding device that is formed of a guide plate main body abutting on recording materials, an arm portion joined to the guide plate main body, and a fixing portion to which the rear end of the arm portion is joined in a rotatable manner, and it is provided with an arm-coupled guide member that aligns the recording materials at the end position. This configuration allows the arm-coupled guide member to abut on the rear ends of sheets when viewed in a transportation direction of transfer sheets and thereby to align the transfer sheets at the rear end position (see claim 1, FIG. 3, and paragraph [0049] in Reference D1).
In Reference D1, a transfer sheet side guide plate is provided perpendicularly to the bottom surface of the sheet feeding device so as to restrict the position of transfer sheets in the width direction. The transfer sheet side guide plate is formed by joining a fixing plate provided with a long hole to a guide plate main body that abuts on transfer sheets in such a manner that the fixing plate becomes perpendicular to the guide plate, and the transfer sheet side guide plate is fixed (supported) by screwing the fixing plate to the side edge of the sheet feeding device (see FIG. 4, paragraphs [0004] and [0043] in Reference D1).
As has been described, the guide to restrict the sheet position is generally provided perpendicularly to the bottom surface inside the sheet feeding device. In Reference D1, too, the guide plate main body in the arm-coupled guide member and the transfer sheet side guide plate in the width direction of sheets are provided so that the both guides become perpendicular to the bottom surface.
When the guides are provided perpendicularly to the bottom surface of the sheet feeding device, however, there arises a problem that the guides lie in the way when the user replenishes sheets to the sheet feeding device. More specifically, the user hits his or her hands (fingers) holding sheets to be replenished against the top ends of the guides, which interferes with a sheet replenishment work. In particular, when the user replenishes sheets of a small size, he or she is more likely to hit his or her hands against the guides and the guides readily cause a nuisance.
Reference D1 has an object to perform the positioning efficiently with ease of operation when sheets are piled, and no consideration is given to an inconvenience that the user hits his or her hands against the guides. Combined with the configuration that the top ends of the guides are square, the user easily hits his or her hands against the respective guide plates when he or she replenishes sheets, which actually makes sheet replenishment difficult.